1. Field of the Invention
The present invention relates generally to engagement devices engaging two members and particularly to such compact engagement devices.
2. Description of the Related Art
FIGS. 6A and 6B show a structure of an engagement device engaging two members relating to the present invention. FIG. 6A is a perspective view of an interface unit 40 to which an information terminal 41 corresponding to one member is to be mounted, although an information terminal 41 corresponding to the other member has not yet been mounted thereto. FIG. 6B shows interface unit 40 with information terminal 41 mounted thereto. Information terminal 41 and interface unit 40 are interconnected via a connection terminal 42.
FIGS. 7A-7C are cross sections more specifically showing how interface unit 40 and information terminal 41 are interconnected. FIG. 7A is a cross section of a main portion of information terminal 41. FIG. 7B is a cross section of a main portion of interface unit 40. FIG. 7C is a cross section showing that information terminal 41 is mounted to interface unit 40.
Referring to FIG. 7A, information terminal 41, not yet mounted to interface unit 40, has a movable contact 52 biased by a spring 54 and thus out of contact with an electrical contact 51 provided internal to information terminal 41.
Referring to FIGS. 6A and 6B and 7A-7C, to mount information terminal 41 to interface unit 40, a set button 43 as shown in FIG. 6A is initially pressed. Thus, as shown in FIG. 7B, the interface unit""s connecting terminal 42 moves in a direction indicated by the arrow. With connecting terminal 42 moving as described above, information terminal 41 is positioned in interface unit 40 on a bottom surface 44. When set button 43 is released with the terminal thus positioned, as shown in FIG. 7C the interface unit""s connecting terminal 42 moves in the direction indicated by the arrow to push and thus bring movable contact 52 of information terminal 41 into contact with an electrical contact 51 of the body of information terminal 41 to allow signal communication therebetween.
There is a heart rate meter worn by joggers and swimmers conventionally on their arms and transmitting the user""s heart rate signal from a sensor to the heart rate meter wirelessly.
If the user desires to use the heart rate meter when riding a bicycle as well as jogging and swimming, the heart rate meter is attached to the bicycle""s handle or the like. This would not particularly be problematic if the bicycle""s speed signal, the crank shaft""s rotation signal and the like as well as the user""s heart rate signal are transmitted to and received from the heart rate meter wirelessly. If any signal generated from the bicycle is transmitted and received via a wire, however, their interface contacts electrically conduct due to the user""s skin, water and the like, resulting in erroneous operation.
To avoid this, it is preferable that normally an external contact and an internal interconnection be disconnected from each other and only as required the external contact and the internal interconnection be connected with each other by the above-described structure connecting interface unit 40 and information terminal 41 together. With such structure, however, interface unit 40 serving as a base is too large in size and it can thus not be mounted on a small space such as a bicycle""s handle.
The present invention therefore contemplates an engagement device capable of readily engaging two members, such as a base unit and a measuring instrument, at a position as desired by the user.
In accordance with the present invention, an engagement device overlaps and thus engages first and second members with each other. The first member has one end provided with a fixed, first engaging feature, and the other end provided with a second engaging feature movable in a first direction corresponding to a direction towards one end of the first member. The second member has third and fourth engaging features engaging with the first and second engaging features, respectively. The first member has a lever moving the second engaging feature in the first direction when the second engaging feature engages with the fourth engaging feature. With the first member overlapping the second member, in a portion other than the lever the first member has a region smaller than the second member.
With the engagement device of the present invention, when the first and second members overlap, in a portion other than the lever for moving the second engaging feature in the first direction the first member occupies an area smaller than the second member. This allows the engagement device to be compact. As a result, there can be provided a device capable of readily connecting together two members, such as a base unit and a measuring instrument, at a position as desired by the user.
Preferably the lever is movable in a second direction traversing the first direction.
Still preferably the lever is biased in a direction opposite to the second direction.
Still preferably the second engaging feature has a portion obliquely traversing both of the first and second directions and the lever slides along the oblique portion to move in the first direction.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.